Jason Venture 4000
The Venture 4000 was Jason's high end line around the late 1960's. The models in this line included two 7x35's, an 8x32, and a 7x25 roof prism. The porro prism models seem to be a response to the Bushnell Custom line - note the similarities in the high quality body design.
Venture 4000 7x35 (Model 100?)
Mfr: J-B22, J-E29
Date: circa late 1960's
AFOV: ~60 degrees
TFOV: ~8.5 degrees, 450 feet at 1000 yards
Eye Relief: ~12-13mm
Prisms: high index
This model has a moderate FOV with fairly good optics but it does not match up to the Bushnell Custom. The image is softer towards the edge and the eye relief is not as good. The body is more compact than the Custom's, though. It has metal screw-up eyecups. The Jason catalog I have shows the Model 100 with a FOV of 420 feet at 1000 yards. My sample, which has a slightly wider field, may be an earlier version.
Venture 4000 7x35 Extra Wide Angle (Model 103)
Mfr: J-B22, J-E29
Date: circa late 1960's
AFOV: ~84 degrees
TFOV: ~12 degrees, 631 feet at 1000 yards
Eye Relief: ~12mm
Prisms: high index
This is an extra wide angle version of the 7x35, probably meant to compete with the Bushnell Rangemaster. It is lighter and more compact than the Rangemaster but I don't think the optics are quite as good. I would still rate it as one of the better wide angle 7x35's though. I seem to detect a bit of spherical aberration of the exit pupil - some shadowing when moving the eyes around. Note that this sample's body has an unusual "tampico" brown color. It has screw-up metal eye-cups.